Q. Other than lysine, do I need to consider adding any other amino acids?
For most cereal grain-soybean meal-based diet mixtures, lysine is usually the first limiting amino acid for pig growth. Although the dietary lysine concentration is a good measure of the overall amino acid adequacy of the diet, other amino acids potentially low are isoleucine, valine, tryptophan, threonine, and methionine. The inadequacy of these latter amino acids can occur when other protein or amino-acid sources are used to replace soybean meal. For example, when plasma protein is used in pig starter diets, the diet is frequently inadequate in methionine.
Q. How important is the calorie:protein (lysine) ratio?
Pigs generally consume the amount of feed that satisfies their energy requirement. Consequently, as the dietary concentration of fat increases, the amount of feed consumed declines. When a lower quantity of feed is consumed such as when fat is added to the diet, it is essential that the energy (calorie):protein (lysine) ratio be maintained. Consequently, as feed intake declines, other dietary nutrients must be adjusted to a higher concentration.
Q. How important is the dietary calcium:phophorus ratio?
The ratio of dietary calcium to phosphorus is important for the optimal absorption and utilization of both minerals. When the diet contains a marginal level of phosphorus, a high calcium:phosphorus ratio will result in a lowered phosphorus absorption. A poor cal-cium:phosphorous ratio can reduce growth rate and bone calcification. A suggested calcium:phosphorus ratio for grain-soybean meal diets ranges between 1.2:1 to 1.5:1.
Q. How important is water quality?
Concerns about water quality are most commonly related to its microbial contamination. Microbial levels higher than 50 colony-forming units per liter are potentially harmful and require corrective action. Microbial levels less than 10 colony-forming units per liter are acceptable.
Q. Where do we get water analyzed?
Your State Board of Health will analyze water for bacterial contamination and nitrates.
Q. What minerals are in the water supply, and what effect do they have on pig performance?
The minerals most commonly found in ground water are iron, sulfate, chloride, and magnesium. These minerals can form chemical complexes with calcium, magnesium, and sodium, and are termed total dissolved solids. Concentrations of total dissolved solids above 5,000 ppm have been reported to cause diarrhea, poor performance, and poor locomotor function in pigs.
Q. Does high iron- or high sulfur-containing water harm pigs?
High iron will clog filters, screens, etc., of water lines. Water with high sulfur content has resulted in increased water consumption but has not been shown to affect pig performance. Extremely high iron and sulfate concentrations have, however, been suspected of causing diarrhea in young pigs.
Q. What other compounds in water are potentially harmful to pigs?
Nitrates are often present in ground and surface water. Nitrates can be converted to nitrites, which are harmful. The conversion to nitrite is necessary for toxicity to occur. Nitrites at levels less than 100 ppm are generally safe, but higher levels convert hemoglobin to methemoglobin. Methemoglobin does not carry an adequate amount of oxygen to the tissues and can result in animal death if an excess level is in the blood.
Q. What is the desired water flow rate in the different pig production phases?
In general, water must be accessible and be available in an ample quantity. Suggested water flow rates from nipple drinkers are:
| Production Phase | Flow Rate |
|---|---|
| Starter pigs (10 - 50 lb.) | 250 to 500 ml/minute (0.5 quart/minute) |
| Grower pigs (50 - 140 lb.) | 500 to 750 ml/minute (0.75 quart/minute) |
| Finisher pigs (140 - 250 lb.) | 750 to 1,000 ml/minute (1.00 quart/minute) |
| Sows and boars | 1,500 ml/minute (1.50 quart/minute) |